There are many classes of compounds that are pharmaceuticals. so called 'small molecules' such as aspirin, have been useful in medicine and pharmacy for years. now scientists are learning how to design small molecules which will accurately react with receptors for more effective medications with fewer side effects. which areas of pharmaceutical drug development have best facilitated small molecule design?

Drugs may be defined as the chemicals substance that might cause change in the physiology of an organisms. Drugs are used legally to treat the particular disease. Excess dose of drugs might cause hallucinations and addiction in the individual.

The pharmaceutical drugs include the combination of the different fields of chemistry to make the new active compound. The pharmacogenomics is newly advanced field including personalized medicine. The chiral chemistry of the drug is quite important for the development of new small molecule design of drug.